1. Field of the Invention
The present invention is related to a connector assembly of modular jacks, especially to a connector assembly having a conditioning unit including a circuit board with magnetic filter/conditioning components mounted on it to condition the signals passing through them.
2. Description of the Related Art
The communication between computers becomes more and more important because of the prevalence of the Internet. People use the Internet or an internal network everyday for their daily work, entertainment, and other personal affairs. However, for each of personal computers or end-user terminals, a mutual intermediary like cables or wires is necessary to connect these computers into a network. The signal transmission speed in such a network depends on the conductivity of the cables, the operation speed of the workstations or servers signal transmitting, and the condition of the environment in which computers and cables are located. Usually the signals transmitted by cables are easily affected because of the diversity and unpredictability of the environment cables meet. Therefore, if signals can be conditioned before they are transmitted, received or used by any electronic device, the performance and working speed of this device will be better and faster. The best way to avoid any noise interference is shielding the cable and device all the time. However, in high frequency and speed situation, any necessary connection is always a deficiency to cause signals interfered by an outer noise source and failing to achieve the perfect transmission. And the cost for a perfect electrical shield is expensive too. Besides, crosstalk always happens between two parallel signal-transmitting conductors. Thus, the signals transmitted by cables or wires should be conditioned first before they are used in any electrical device like computers due to their noise problem. Especially, to mount a conditioning component, such as a common mode choke coil, filter circuit or transformer, into any I/O connector of these devices is a good way because the I/O connector is always the last or important one of the necessary connections should be well shielded for a perfect transmission. Sakamoto et al. U.S. Pat. No. 5,139,442 introduces such a modular jack connector having a built-in common-mode choke coil. However, to use wires of the coil as contactors of the modular jack connector cause more complicated assembling process always costs high and is time-consuming. Therefore U.S. Pat. No. 5,687,233 issued to Loudermilk et al. discloses a built-in printed board containing a noise suppressing electronic element like transformer is received in the modular jack connector. It is obviously laborsaving because the contactors of the connector are mounted to the printed board after the filter circuit and related electronic elements are mounted onto the printed board in advance. And more signal contactors can be used and assembled at the same time by increasing necessary number of the electronic elements and their corresponding circuits on the board beforehand.
The method adopted in Loudermilk et al. needs to be improved due to the expensive cost to produce its built-in printed board and still complicated process to assemble the printed board and the connector housing. Especially the isolated contactors of the connector should be well sustained when they are assembled into the connector housing together with the printed board. And in the multi-port application, the increasing contactors need to be mounted onto the motherboard will make it much more difficult to dispose or assemble the built-in printed board. U.S. Pat. Nos. 5,587,884 and 5,647,767 disclose a subassembly inserted into the housing of the modular jack connector. The subassembly includes a front insert member having contact terminals and a rear insert member having a printed board with conditioning components mounted thereon. Better support from these two insert members will effectively sustain the terminals and other components when the subassembly is inserted into the connector housing and fastened therein during the assembling process. However, much more procedures are needed to manufacture the subassembly and most of them like insert-molded parts cost expensively. Besides, new parts are needed in the multi-port application. Minich U.S. Pat. No. 6,022,245 shows a modular connector having two stack plug receiving ports. Two retainers holding terminals in the connector housing and a printed board having filter components and an edge connector to connect the printed board to the motherboard where the modular connector is seated. After the retainers and terminals are properly installed into the housing, the printed circuit board is installed into the housing and ends of terminals make resilient contact to the printed board. Installing support to every terminal is enough again and the simplified process will be adopted to produce each of necessary parts. However, in this case, too many parts are needed and the assembling process is still complicated and labor consuming. And more fixture mechanism in the housing is needed to put each of these parts in position.
In conclusion, it is understandable that most of methods adopted by these prior arts mentioned above have a complicated process, especially when assembling. Meanwhile, it is difficult to dismantle parts if some of them fail to work. Some of parts disclosed in prior art are vulnerable when removing from the housing. That means it is impossible to rework or repair on them if some of them need to change. Furthermore, no parts in prior art can be used in another product applications having a different number of mating ports.